JP5411775B2 - Work vehicle swivel transmission - Google Patents

Description

  The present invention relates to a turning transmission device for a work vehicle that can drive a pair of left and right traveling devices separately based on operation of a steering operation tool.

  Conventionally, for example, as shown in Patent Document 1, a drive gear ("center gear" in the literature) that is supported by a support shaft installed on a transmission case and rotated by the driving force of an engine, and both left and right sides of the drive gear Each of the steering operation tools is engaged with a pair of left and right drive transmission gears (referred to as “running transmission gears” in the literature) that are externally rotatably mounted on the respective support shafts and linked to the pair of left and right traveling devices. There was a turning transmission device provided with a pair of left and right slide members ("small-diameter clutch gear" in the literature) that can move relative to each other along the support shaft by the above operation and can be engaged with each other separately. The swing transmission device described in Patent Document 1 is slidable with respect to the first friction plate and the transmission case side member that are slidably engaged with the slide member on both the left and right sides of the drive gear. A plurality of engaged second friction plates are alternately disposed and provided on the slide member by separating the slide member from the drive gear after the slide member and the drive gear are disengaged. A moving pressing portion that can press the first friction plate or the second friction plate along the support shaft, and a stationary pressing portion that is a member on the mission case side and faces the moving pressing portion (in the literature, “large-diameter clutch gear”) ) And a pair of left and right wet multi-plate clutches (referred to as “turning assist clutch” in the literature) configured to sandwich the first friction plate and the second friction plate.

  In the turning transmission device for a work vehicle described in Patent Document 1, when the wet multi-plate clutch is in the “clutch engaged state”, a driving force at a speed different from the driving force via the center gear is applied to the slide member from the transmission case side. Is transmitted. That is, this turning transmission device gives a drive rotation difference to the left and right traveling devices by the movement of the slide member based on the operation of the steering operation tool ("steering operation lever" in the literature), and responds to the driver's request. The work vehicle is turned with a turning radius. With this device, for example, a “slow turn” that turns with a relatively large radius by disconnecting the transmission system between the drive transmission gear and the drive gear on the turning direction side, and a brake on the drive transmission gear on the turning direction side is applied. By applying a driving force in the direction opposite to the traveling direction to the drive transmission gear on the side of the turning direction by applying the “revolution turning” that turns about the traveling device on the side of the turning direction by applying it It is possible to perform “super-spinning turning”.

JP 2007-303637 A

  The multi-plate clutch means that when the first friction plate and the second friction plate are in contact with each other with no gap, the first friction plate and the second friction plate are further narrowed and both friction plates are caused by their friction force. Are rotated together and the force is transmitted. In a multi-plate clutch, the state in which the first friction plate and the second friction plate are spaced apart and irregularly arranged is the “clutch disengaged state”, and the first friction plate and the second friction plate are aligned without gaps. Thus, the state in which the two friction plates can be rotated together integrally (the state in which the relative rotation is stopped) is the “clutch engaged state”. Between the clutch disengaged state and the clutch engaged state, the first friction plate and the second friction plate are aligned without gaps and contact with each other to generate a frictional force, but the friction plates still rotate relative to each other. There is a “half-clutch state”. For example, in the turning transmission device described in Patent Document 1, in the half-clutch state, the first friction plate and the second friction plate are aligned without a gap, and both of them are caused by the narrow pressure between the moving pressing portion and the stationary pressing portion. The magnitude of the frictional force generated between the friction plates is determined.

  However, when a large number of components are used, the slide member may be inclined with respect to the support shaft based on a processing error between the components, and the moving pressing portion provided on the slide member may also be inclined with respect to the support shaft. When the moving pressing portion is in a half-clutch state with the moving pressing portion tilted with respect to the support shaft, the friction plate and the moving pressing portion closest to the moving pressing portion may come into contact with each other and abnormal noise may be generated. Even if the slide member is not inclined with respect to the support shaft, if the pressing surface of the moving pressing portion is uneven, there is a possibility that one-sided contact will occur and abnormal noise may occur.

  Also, the pressing force of the moving pressing part is transmitted to the stationary pressing part via all the friction plates, and the stationary pressing part is also the most pressing side of the stationary pressing part with the same force as the pressing force of the moving pressing part based on the relationship of action and reaction. Press the friction plate. Therefore, even when the pressing surface of the stationary pressing portion has irregularities, there is a possibility that abnormal noise may be generated due to contact between the stationary pressing portion and the friction plate closest to the stationary pressing portion.

  In view of the above circumstances, an object of the present invention is to provide a turning transmission device for a work vehicle that does not generate abnormal noise in a half-clutch state during turning.

  A first characteristic configuration of a turning transmission device for a work vehicle according to the present invention is a turning transmission device for a work vehicle including a pair of left and right traveling devices that can be driven separately based on the operation of a steering operation tool. A drive gear supported by a support shaft installed on the case and driven to rotate by the driving force of the engine, and on both the left and right sides of the drive gear, each of the drive gears is externally rotatably mounted on the support shaft. A pair of left and right that can be engaged with each of the drive gears by moving relative to each other along the support shaft by operation of the steering operation tool while always meshing with each of the pair of left and right drive transmission gears respectively linked to the traveling device. And the first friction plate slidably engaged with the slide member on both the left and right sides of the drive gear and the member on the transmission case side. A plurality of second friction plates that are freely engaged are alternately disposed, and after the engagement between the slide member and the drive gear is released, the slide member is separated from the drive gear, A movable pressing portion provided on the slide member and capable of pressing the first friction plate or the second friction plate along the support shaft, and a member on the side of the transmission case, facing the moving pressing portion. A pair of left and right wet multi-plate clutches configured to sandwich the first friction plate and the second friction plate, and a friction plate closest to the moving pressing portion or the most stationary pressing portion. An annular tilting portion that is disposed to face the friction plate on the side of the slide member and is tiltable with respect to the slide shaft core of the slide member by pressing of the moving pressing portion, and is disposed around the support shaft An automatic inclination interposed between the moving pressing portion and the friction plate closest to the moving pressing portion, or between the stationary pressing portion and the friction plate closest to the stationary pressing portion. And a correction unit.

  With this configuration, the narrow pressure generated by the moving pressing portion and the stationary pressing portion acts on at least one of the first friction plate and the second friction plate via the automatic inclination correction portion. Moreover, the automatic inclination correction part has a tilting member, and the tilting member is tiltable with respect to the slide member by the pressing of the moving pressing part. Therefore, when a narrow pressure is applied to the automatic inclination correcting unit from the moving pressing unit or the stationary pressing unit, the tilting member moves most when it contacts the friction plate closest to the moving pressing unit or the friction plate closest to the stationary pressing unit. It tilts along the friction plate on the pressing portion side or the friction plate on the most stationary pressing portion side. As a result, the narrow pressure on the friction plate does not act in a one-sided state, and no abnormal noise is generated when the half-clutch state is reached.

  According to a second characteristic configuration of the turning transmission device for a work vehicle according to the present invention, the automatic inclination correcting portion is externally fitted to the slide member, the slide member is extrapolated, and the moving pressing portion. The tilting member that presses the friction plate on the most moving pressing portion side through the base member by pressing, and a plurality of ball members interposed between the base member and the tilting member, A spherical surface centered on a point on the slide axis, at least one of a surface of the base member facing the tilting member and a surface of the tilting member facing the base member It is in the point formed along the shape.

  With this configuration, the tilting member can freely tilt with respect to the base member along the surface of a sphere centered on a point on the slide axis by free rotation of the ball member. Therefore, it is possible to prevent the generation of abnormal noise when the clutch is in a half-clutch state, simply by providing an automatic inclination correcting unit having a simple configuration such as a base member, a ball member, and a tilting member. Further, since the base member and the tilting member need only be extrapolated to the slide member, assembly and disassembly are easy. Furthermore, since the spherical surface formed on the base member or the spherical surface formed on the tilting member is centered on a point on the slide axis, tilting of the tilting member does not have directivity, and the tilting member is in any direction. Can be tilted smoothly. Therefore, regardless of the direction in which the base member is tilted following the inclination of the moving pressing portion, the tilting member follows the friction plate closest to the moving pressing portion or the friction plate closest to the stationary pressing portion. Tilt reliably to.

These are the whole left views of the combine which concerns on this invention. These are figures which show the gear train of the transmission system of the driving force to each part. These are hydraulic circuit diagrams which transmit operation of a steering lever. These are the longitudinal cross-sectional front views of a turning transmission device when the left side brake is in a half brake state. (A) is a longitudinal front view of the automatic inclination correction unit in the brake-off state, and (b) is a longitudinal front view of the automatic inclination correction unit in the half-brake state. These are exploded sectional views of an automatic inclination correction part. FIG. 3 is an exploded perspective view of an automatic inclination correction unit. These are figures explaining the state of a side brake based on the state of each part. These are the longitudinal cross-sectional front views of the transmission system of the driving force in 3rd another embodiment. These are figures which show the gear train of the transmission system which concerns on 4th another embodiment. These are hydraulic circuit diagrams which concern on 4th another embodiment. These are the longitudinal cross-sectional front views of the turning transmission which concerns on 4th another embodiment. These are the longitudinal cross-sectional front views of the left side brake which concerns on 4th another embodiment. These are the figures explaining the state of the side brake which concerns on 4th another embodiment. These are the longitudinal cross-sectional front views of the left side brake which concerns on 5th another embodiment. These are figures which show the gear train which concerns on 6th another embodiment.

  Hereinafter, an example in which the present invention is applied to a self-removing combine turning transmission device will be described with reference to the drawings.

[Overall structure of the combine]
The combine according to the present invention is a self-removing combine harvester that harvests rice, wheat, etc., and as shown in FIG. 1, a pair of left and right crawler-type travelings that support a body frame 1 and a body frame 1 that is a skeleton of the body. The device 2 (in particular, the left traveling device is represented as 2L and the right traveling device is represented as 2R), the cutting unit 3 connected to the front of the body frame 1, and the rear side of the body frame 1 The threshing device 4 and the glen tank 5 are provided. The threshing device 4 includes a threshing feed chain 9 on the left side of the machine body. In addition, on the front side of the fuselage frame 1, a driving unit 6 having a driver seat on the right side of the fuselage is provided.

  The engine E (see FIG. 2) is provided below the operation unit 6. Further, a traveling transmission device 7 is provided at the front end of the body frame 1. The driving force output from the engine E is shifted by the traveling transmission device 7 and transmitted to the traveling device 2. Thereby, the traveling device 2 is driven, and the combine travels.

[Engine drive power transmission system]
A transmission system in which the driving force of the engine E is transmitted to the traveling device 2, the mowing unit 3, and the threshing device 4 will be described with reference to FIG.

  As shown in FIG. 2, the output shaft of the engine E and the input shaft of the threshing device 4 are linked by a transmission belt, and the driving force of the engine E is the threshing feed chain 9 (see FIG. 1) or a handling cylinder (not shown). Or to a sorting device.

  Next, a structure in which the driving force of the engine E is transmitted to the traveling device 2 and the cutting unit 3 will be described. The travel transmission device 7 includes a hydrostatic continuously variable transmission (hereinafter referred to as “HST”) 50 as a travel main transmission unit and a travel mission unit 60. The output shaft of the engine E and the input shaft 53 of the HST 50 are linked by a transmission belt. As a result, the driving force of the engine E is transmitted to the HST 50. The HST 50 is accommodated in the transmission case TC. The HST 50 includes an axial plunger type hydraulic pump 51 having a variable capacity, and an axial plunger type hydraulic motor 52 driven by pressure oil from the hydraulic pump 51. The input shaft 53 is connected to the hydraulic pump 51 and is rotatably supported by the transmission case TC. The driving force of the engine E transmitted to the HST 50 is converted into a forward driving force or a backward driving force by the HST 50 and output from the output shaft 54 connected to the hydraulic motor 52. The HST 50 can change the driving force steplessly on both the forward side and the reverse side.

  The traveling mission unit 60 is accommodated in a mission case MC that is disposed adjacent to the lower side of the traveling machine body of the transmission case TC. The traveling mission unit 60 includes a traveling auxiliary transmission unit 61, a turning transmission device 62, and a drive transmission shaft 63. The output shaft 54 of the HST 50 is rotatably supported across the transmission case TC and the transmission case MC. In the mission case MC, the output shaft 54, the input shaft to the cutting portion 3 side, and the input shaft of the traveling auxiliary transmission portion 61 are gear-coupled to each other. Thereby, the driving force output from the HST 50 is transmitted to the cutting unit 3 and the traveling auxiliary transmission unit 61 separately.

  The traveling sub-transmission unit 61 decelerates the driving force transmitted from the HST 50 with three kinds of reduction ratios and transmits it to a center gear 72 described later in the turning transmission device 62.

  The drive transmission shaft 63 is rotatably supported by the transmission case MC on the lower side of the traveling machine body of the turning transmission device 62. On the drive transmission shaft 63, a pair of left and right drive transmission gears 64 (in particular, the left side drive transmission gear 64L and the right side drive transmission gear 64R are rotatably supported). . The driving force transmitted from the center gear 72 is transmitted separately to the left and right drive transmission gears 64L and 64R via the turning transmission device 62.

  The left and right traveling apparatuses 2 are connected to the crawler driving wheel body 21 that rotationally drives the traveling apparatus 2, the traveling drive shaft 22 that is rotatably supported by the transmission case MC, and the traveling drive. A traveling gear 23 fitted to the shaft 22 (in particular, the left traveling gear is referred to as 23L, and the right traveling gear is referred to as 23R in particular) is provided. The left drive transmission gear 64L and the left travel gear 23L are always meshed. When the driving force is transmitted from the left drive transmission gear 64L to the left travel gear 23L, the left travel device 2L is driven. Similarly, the right drive transmission gear 64R and the right travel gear 23R are always engaged, and when the driving force is transmitted from the right drive transmission gear 64R to the right travel gear 23R, the right travel device 2R is driven. To do.

(Swivel transmission device)
The turning transmission device 62 will be described in detail with reference to FIGS. The turning transmission device 62 operates by operating a steering lever 8 (see FIG. 3) as a “steering operation tool” provided in the operation unit 6. By operating the turning transmission device 62, the transmission system of the driving force of the engine E to the traveling device 2 and the brake to the traveling device 2 after the transmission system is disconnected are divided into the left and right traveling devices 2L, 2R. Can be performed separately on the left and right. That is, the turning transmission device 62 gives a driving speed difference to the left and right traveling devices 2L and 2R. As a result, the combine driver can select and perform “slow turn” and “trust turn”, which will be described later, during turning.

  As shown in FIGS. 2 and 4, the turning transmission device 62 includes a support shaft 71 that is rotatably supported by the transmission case MC, a center gear 72 as a “drive gear” that is rotatably supported by the support shaft 71, and On both the left and right sides of the center gear 72, a pair of left and right clutch gears 73 are mounted so as to be rotatable relative to the support shaft 71, and the left and right traveling devices 2L are moved by the movement of the clutch gear 73 on the support shaft 71. , 2R, and a pair of left and right "wet multi-plate clutches" as a side brake 74 and an automatic inclination correcting unit 40 are provided.

  As shown in FIG. 4, both ends of the support shaft 71 are supported via a bearing R by a brake cover BC mounted on the transmission case MC. The left and right brake covers BC are detachably attached to the mission case MC with a plurality of bolts. The brake cover BC includes a bearing holding part BC1 and a mounting part BC2. The bearing holding part BC1 is formed in a bag shape protruding outward, and the bearing R is fitted into the bearing holding part BC1. The attachment portion BC2 is formed by extending the outer peripheral portion of the bearing holding portion BC1 in the radially outward direction. A plurality of bolt holes are formed in the attachment portion BC2, and the brake cover BC is tightened to the transmission case MC by bolting. Installing.

  As described above, the center gear 72 is rotated by the driving force of the engine E from the traveling subtransmission unit 61. On both side surfaces of the center gear 72, locked portions 72a that are block-like irregularities are formed along the circumferential direction.

  Since the left and right clutch gears 73 are symmetrical with respect to the center gear 72, only the left clutch gear 73 will be described here. As shown in FIG. 4, the clutch gear 73 is externally slidably mounted on the support shaft 71, and the slide shaft core L <b> 1 of the clutch gear 73 is generally substantially coincident with the shaft core L of the support shaft 71. At the end of the clutch gear 73 on the side of the center gear 72, a locking portion 73a having a shape corresponding to the locked portion 72a is formed. The clutch gear 73 can be relatively moved along the support shaft 71 by the operation of the steering lever 8, and the engaged portion 72a and the engaging portion 73a are engaged by the relative movement (the right clutch gear 73). (Left side of FIG. 4), and the bite is disengaged (left clutch gear 73 state, right side of FIG. 4). A gear portion 73b is formed on the outer peripheral surface of the clutch gear 73, and this gear portion 73b is always meshed with the left drive transmission gear 64L. Therefore, when the locked portion 72 a and the locking portion 73 a are engaged, the clutch gear 73 rotates integrally with the center gear 72, and the driving force of the engine E is transmitted to the drive transmission gear 64. On the other hand, when the engagement of the locked portion 72a and the locking portion 73a is released, the driving force of the engine E is not transmitted to the left drive transmission gear 64L.

  The clutch gear 73 is a cylindrical member that is rotatably inserted on the support shaft 71. As shown in FIG. 4, the inner peripheral portion of the clutch gear 73 is expanded from the middle in the longitudinal direction, and a space is provided between the shaft 71 and the support shaft 71. The spring 75 is inserted and disposed in this space so as to extend over the stepped portion 73 c and the bearing R in the enlarged diameter portion of the inner peripheral portion of the clutch gear 73. The spring 75 biases the clutch gear 73 toward the center gear 72 so as to mesh with the center gear 72.

  As shown in FIG. 3, the combine is operated as a system that transmits the operation of the steering lever 8 to the clutch gear 73, and is switched by the hydraulic pump 12 that discharges oil from the oil tank 11 and the steering lever 8. A control valve 13 of a three-position switching type that controls the supply and discharge of pressure oil from 12, a cylinder block 14 into which pressure oil from the control valve 13 can flow, and a pair of cylinders 14 that are detachably mounted in the cylinder block 14 Plunger 15 (in particular, the left plunger is called 15L and the right plunger is called 15R) and the clutch gear 73 is engaged with the outer peripheral surface, and the plungers 15R and 15L are rotated by the withdrawal and withdrawal. Then, the operating arms 16 for operating the left and right clutch gears 73 separately (in particular, the left operating arm is 16L and the right operating arm is 16R. Referred to as), and a. A spring 17 is disposed between the cylinder block 14 and the plunger 15, and the spring 17 biases the plunger 15 toward the side where the plunger 15 is retracted.

  The steering lever 8 is configured to be swingable left and right. When the steering lever 8 is in the neutral state N, no pressure oil acts on the plunger 15, and the plunger 15 is retracted to the cylinder block 14 as much as possible. At this time, the operation arm 16 does not rotate, and the left and right clutch gears 73 remain engaged with the center gear 72, respectively. Therefore, the driving force at the same speed is transmitted to the left and right traveling devices 2L and 2R, and the combine moves straight.

  Although not particularly illustrated, when the steering lever 8 is changed from the neutral state N to the state L1, the left plunger 15L protrudes and the left operation arm 16L rotates. The left operation arm 16L moves the clutch gear 73 to the left, and the engagement between the clutch gear 73 and the center gear 72 is released. As a result, the transmission of the driving force to the left traveling device 2L is cut off, and the combine performs a so-called “slow turn” in which the turn turns to the left side with a relatively gentle rotation locus. Subsequently, when the steering lever 8 is further swung to the left to bring it to the state L2, the left operating arm 16L moves the clutch gear 73 further to the left, and the left side brake 74 described later is in the braked state. Become. As a result, the left traveling device 2L is braked, and the combine performs a so-called “belief turn” in which the combine turns around the left traveling device 2L and turns leftward.

  The same applies when the steering lever 8 is swung to the right. When the state R1 is set, the combine "turns gently" to the right, and when the state R2 is set, the combine "turns" to the right.

〔side brake〕
The side brake 74 brakes the left and right traveling devices 2R and 2L separately based on the operation of the steering lever 8. When the left side brake 74 is in the braked state, it is possible to turn to the left, and when the right side brake 74 is in the braked state, it is possible to turn to the right. Since the left and right side brakes 74 have a symmetrical configuration, only the configuration of the left side brake 74 will be described here, and the configuration of the right side brake 74 will not be described. The turning transmission device 62 including the side brake 74 is enclosed by a mission case MC or the like as an oil bath.

  As shown in FIG. 4, the side brake 74 is slidably engaged with the first friction plate 74 a slidably engaged with the clutch gear 73 (integrally rotatable) and the transmission case MC ( A plurality of second friction plates 74b, which cannot be rotated, are arranged alternately.

  Specifically, a plurality of projecting portions 74c serving as “members on the transmission case side” projecting toward the flange portion 73d on the portion facing the side surface of the center gear 72 of the brake cover BC, that is, the mounting portion BC2. Is formed upright. The projecting portions 74c are integrally formed with the attachment portion BC2 in a state of being separated from each other on the same circumference around the axis L. An intermediate portion in the direction of the axis L of the outer peripheral portion of the clutch gear 73 is protruded radially outward to form a flange portion 73d as a “moving pressing portion”. A stationary pressing portion 74d that protrudes annularly on the flange portion 73d side is integrally formed on the attachment portion BC2 facing the flange portion 73d. The stationary pressing portion 74d is formed at a position inside the protruding portion 74c.

  A plurality of first friction plates 74 a are spline fitted to the outer periphery of the clutch gear 73. In addition, a plurality of second friction plates are formed by projecting several circumferential portions of the outer peripheral portion of the second friction plate 74b in the radially outward direction and inserting the projections between the projecting portions 74c. 74b is engaged with the protruding portion 74c. After the clutch gear 73 and the center gear 72 are disengaged, the clutch gear 73 moves in a direction away from the center gear 72, so that the flange portion 73d and the stationary pressing portion 74d move between the first friction plate 74a and the second friction plate 74a. The plate 74b can be clamped and braked.

[Automatic tilt correction part]
As shown in FIG. 5, the automatic inclination correcting part 40 is interposed between the flange part 73d and the friction plate closest to the flange part 73d. The automatic inclination correcting unit 40 can be brought into contact with the flange portion 73d in the direction of the axis L, and can be moved toward the stationary pressing portion 74d by moving the flange portion 73d toward the stationary pressing portion 74d. As shown in FIGS. 6 and 7, the automatic inclination correcting unit 40 includes an annular base member 41, a ball member 42, an annular outer member 43, and an annular inner member 44.

  As shown in FIGS. 6 and 7, the outer member 43 includes a cylindrical portion 43 a along the slide axis L <b> 1 of the clutch gear 73, and a bent portion 43 b obtained by bending the cylindrical portion 43 a in an L-shaped cross section in the radial inner direction. I have. The inner member 44 includes a cylindrical portion 44 a along the slide axis L <b> 1 and a bent portion 44 b obtained by bending the cylindrical portion 44 a in an L-shaped cross section in the radially outward direction, and can be inserted into the outer member 43. Cutout portions 44c that can receive the ball member 42 are recessed and formed at equal intervals in seven locations on the outer peripheral portion of the bent portion 44b. A part of the outer peripheral portion of the cylindrical portion 44a is cut into an R shape on the inner side of the cutout portion 44c. The maximum width of the notch 44 c in the radial direction is substantially equal to the diameter of the ball member 42, but the maximum width of the notch 44 c in the direction of the slide axis L 1 is smaller than the diameter of the ball member 42. The outer diameter of the cylindrical portion 44a is substantially equal to the inner diameter of the bent portion 43b, and the outer diameter of the bent portion 44b is substantially equal to the inner diameter of the cylindrical portion 43a. As described above, the inner peripheral shape of the outer member 43 and the outer peripheral shape of the inner member 44 correspond to each other. When the inner member 44 is inserted into the outer member 43, the bent portion 43b and the bent portion 44b come into contact with each other, The member 44 is restrained from further movement in the insertion direction. When the bent portion 43b and the bent portion 44b are in contact with each other, the bent portion 44b does not protrude from the inner peripheral space of the outer member 43 in the direction of the slide axis L1.

  When the inner member 44 is inserted into the outer member 43, a recess capable of holding the ball member 42 is formed by the inner peripheral surface of the outer member 43 and the cutout portion 44c. The ball member 42 is dropped into this recess. Then, by inserting the stopper ring 45 into the annular groove 43c formed in the inner peripheral portion of the outer member 43, the ball member 42 is moved in the direction of the slide axis L1 as shown in FIGS. 5 (a) and 5 (b). Although some movement is possible, the inner member 44 does not come out of the recess in the direction of the slide axis L1 and the inner member 44 does not come out of the outer member 43 in the direction of the slide axis L1. At least a part of the ball member 42 protrudes from the recess.

  As shown in FIG. 6 and FIG. 7, radial irregularities are formed on the inner peripheral portion of the base member 41 so that the outer peripheral portion of the clutch gear 73 can be splined along the direction of the slide axis L1. Yes. The outer diameter of the base member 41 is smaller than the inner diameter of the cylindrical portion 43 a of the outer member 43, and the base member 41 can enter the outer member 43. A surface 41a of the base member 41 that enters the outer member 43 (hereinafter referred to as a “contact surface”) 41a is a spherical surface centered on a point on the central axis of the base member 41, that is, a point O on the slide axis L1. It is formed into a shape.

  As shown in FIG. 5, the automatic inclination correcting unit 40 is extrapolated from the end of the clutch gear 73 in the order of the base member 41, the outer member 43 incorporating the ball member 42, and the inner member 44. The inner diameter of the inner member 44 is set slightly larger than the outer diameter of the clutch gear 73. Further, the outer diameter of the outer member 43 is set slightly smaller than the inner diameter of the protruding portion 74c. As described above, a predetermined gap for allowing the outer member 43 and the inner member 44 to tilt is formed between the outer member 43 and the inner member 44 and the projecting portion 74 c and the base member 41. . Therefore, the outer member 43 and the inner member 44 incorporating the ball member 42 can be tilted with respect to the slide axis L1 and can be relatively rotated with respect to the clutch gear 73 in the circumferential direction. However, a stopper ring 76 is disposed on the inner peripheral portion of the projecting portion 74c, and the outer member 43 and the inner member 44 incorporating the ball member 42 are provided with the projecting portion 74c as shown in FIG. Never get out of it. As a result, the second friction plate 74b does not come out of the protruding portion 74c. The base member 41 is spline-fitted to the clutch gear 73, and the base member 41 is located with respect to the clutch gear 73 along the slide axis L1 in a state where the point O is positioned on the slide axis L1 (axis L). Relative movement is possible.

  With the above configuration, as shown in FIGS. 5A and 5B, when the base member 41 moves along the slide axis L <b> 1 and enters the circumference of the outer member 43, the contact surface 41 a becomes in contact with the ball member 42. Contact. Since the ball member 42 can freely rotate along the contact surface 41a, the outer member 43 and the inner member 44 can freely tilt about the point O on the slide axis L1 along the contact surface 41a. That is, the outer member 43 and the inner member 44 correspond to the “tilting member” according to the present invention.

[Brake operation]
First, each state of the side brake 74 will be described with reference to FIG. When the clutch gear 73 gradually moves to the side brake 74 side based on the operation of the steering lever 8 from the state where the clutch gear 73 is completely engaged with the center gear 72 shown in FIG. The bite with 72 is released. Thereby, the driving force from the engine E is interrupted and the combine turns slowly. When the clutch gear 73 further moves to the side brake 74 side, the flange portion 73d comes into contact with the base member 41, subsequently the base member 41 comes into contact with the ball member 42, and further, the ball member 42 comes into contact with the outer member 43 and the inner member. 44 is contacted. Then, following the movement of the clutch gear 73, the entire automatic inclination correcting section 40 moves, and at least the outer member 43 of the outer member 43 and the inner member 44 comes into contact with the friction plate closest to the clutch gear 73. Thereafter, the gap between the first friction plate 74a and the second friction plate 74b is closed by the movement of the clutch gear 73. When there is no gap between the first friction plate 74a and the second friction plate 74b, the clutch gear 73 cannot move any further. Up to this state, the first friction plate 74a and the second friction plate 74b are relatively rotatable, and this state in which the side brake 74 is not braked is a brake disengaged state as a “clutch disengaged state”.

  Further, when the clutch gear 73 is continuously pressed, the first friction plate 74 a and the second friction plate 74 b are narrowed by the stationary pressing portion 74 d and at least the outer member 43. As the narrow pressure increases, the relative rotation of the first friction plate 74a and the second friction plate 74b decreases due to the mutual friction, and finally the relative rotation stops. That is, the traveling device 2 is completely braked. This state is the brake applied state as the “clutch engaged state”. When the brake is applied, the combine turns in a right or left direction. A state between the brake disengaged state and the brake applied state, and a state in which both friction plates are rotating relative to each other while being subjected to the action of a narrow pressure, is a half brake state as a “half clutch state”.

[Tilt correction operation by automatic tilt correction unit]
The automatic inclination correcting unit 40 performs its function in the half brake state. In the half brake state, there is no gap between the first friction plate 74a and the second friction plate 74b as shown in FIG. 5B, so that the pressing force of the clutch gear 73 acts on the base member 41 and the clutch It is a reaction of the pressing force of the gear 73, and the pressing force from the stationary pressing portion 74 d via both friction plates acts on at least the outer member 43. Since the outer member 43 and the inner member 44 can be tilted with respect to the base member 41 by the rotation of the ball member 42, the flange portion 73d is tilted with respect to the slide axis L1 when pressed due to a processing error or the like. Even if the stationary pressing part 74d is not parallel, the outer member 43 follows the inclination of the stationary pressing part 74d through the friction plate by the rotation of the ball member 42 with respect to the contact surface 41a. That is, the outer member 43 comes into contact with the friction plate substantially in parallel. That is, the contact area of the outer member 43 with respect to the friction plate is large, and no abnormal noise is generated due to one piece. The automatic inclination correction unit 40 functions throughout the half brake state, and no abnormal noise is generated. When the brake is applied, the rotation of the first friction plate 74a is absolutely stopped, so that no abnormal noise is generated.

[First embodiment]
In the above-mentioned embodiment, although the automatic inclination correction | amendment part 40 was provided between the flange part 73d and the friction plate nearest to the flange part 73d, it is not restricted to this. Although not shown, the automatic inclination correcting unit 40 may be provided between the stationary pressing unit 74d and the friction plate closest to the stationary pressing unit 74d. The narrow pressure acting on the friction plate is due to the pressing force by the clutch gear 73 and the pressing force by the stationary pressing portion 74d which is the reaction of the pressing force. can get.

[Second Embodiment]
In the embodiment described above, the contact surface 41a is formed on the base member 41 and the ball member 42 is held on the outer member 43 side. However, the present invention is not limited to this, and the ball member 42 is held on the base member 41 side. A contact surface may be formed on the outer member 43 side.

[Third Embodiment]
An example in which an oil circulation mechanism 80 that circulates oil inside the side brake 74 is provided in addition to the configuration of the above-described embodiment will be described with reference to the drawings. In the combine, especially, the left turn is frequently performed. Therefore, the oil temperature in the left side brake 74 tends to be high due to frictional heat. Therefore, an oil circulation mechanism is provided to circulate the oil in the left side brake 74 and suppress an increase in the oil temperature. Except for the configuration of the oil circulation mechanism, the configuration is the same as that of the above-described embodiment, and will not be described.

  As shown in FIG. 9, the oil circulation mechanism 80 includes a circulation pump 81 connected to the hydraulic pump 51 of the HST 50 and driven by the rotation of the hydraulic pump 51. An oil introduction port 82 is erected on the bearing holding part BC1 toward the outside of the brake cover BC, and the oil introduction port 82 and the discharge port of the circulation pump 81 are connected by a supply oil passage 84. Further, an oil discharge port 83 is erected on the outer peripheral surface of the axle case SC that covers the right traveling drive shaft 22 in the transmission case MC so as to face the outside of the transmission case MC. Are connected by a discharge oil passage 85.

  When the circulation pump 81 is driven, oil around the support shaft 71, particularly oil around the left side brake 74 circulates. More specifically, the oil includes a circulation pump 81, a supply oil passage 84, an oil introduction port 82, a gap between the inner race and the outer race of the bearing R, a gap between the first friction plate 74a and the second friction plate 74b, and drive transmission. The clearance between the shaft 63 and the transmission case MC, the clearance between the right traveling gear 23R and the transmission case MC, the clearance between the inner race and the outer race of the bearing R that supports the traveling drive shaft 22, the traveling drive shaft 22 and the transmission case MC. And the oil discharge port 83, the discharge oil passage 85, and the circulation pump 81.

  Since the circulation pump 81 is driven by the rotation of the hydraulic pump 51, the circulation pump 81 is always driven during the combine traveling. For this reason, an excessive rise in the oil temperature in the vicinity of the left side brake 74 is prevented during the combine traveling.

[Fourth embodiment]
In the above-described embodiment, the example in which the automatic inclination correcting unit is configured by the base member 41, the ball member 42, the outer member 43, and the inner member 44 is shown, but other configurations may be used. For example, an example in which the automatic inclination correcting unit is configured by a disc spring 31 will be described with reference to FIGS. Except for the configuration of the automatic inclination correction unit, the configuration is the same as that of the above-described embodiment, and thus will not be described.

(About overall structure)
As shown in FIGS. 10 to 12, the turning transmission device 62 includes a support shaft 71 rotatably supported by the transmission case MC, a center gear 72 as a “drive gear” rotatably supported by the support shaft 71, On both the left and right sides of the center gear 72, a pair of left and right clutch gears 73 are mounted so as to be rotatable relative to the support shaft 71, and the left and right traveling devices 2L are moved by the movement of the clutch gear 73 on the support shaft 71. , 2R are provided with a pair of left and right side brakes 74 as "wet multi-plate clutches", a disc spring 31 as an "automatic inclination correcting unit", and a thrust collar 32.

  An annular spring accommodating member 77 serving as a “moving pressing portion” is spline-fitted on the outer peripheral portion of the clutch gear 73 closer to the friction plate than the flange portion 73 d. The spring accommodating member 77 is a member that accommodates a disc spring 31 described later. A stationary pressing portion 74 d that protrudes annularly on the spring accommodating member 77 side is integrally formed on the attachment portion BC <b> 2 that faces the spring accommodating member 77. The stationary pressing portion 74d is formed at a position inside the protruding portion 74c.

  After the clutch gear 73 and the center gear 72 are disengaged, the clutch gear 73 moves in a direction away from the center gear 72, whereby the pressing force of the clutch gear 73 is described later via the flange portion 73d and the disc spring 31. It is transmitted to the thrust collar 32, and the thrust collar 32 and the stationary pressing portion 74d can pinch the first friction plate 74a and the second friction plate 74b to perform brake braking.

(About disc spring and thrust collar)
The disc spring 31 is annular, and its outer diameter is increased (or reduced) toward one direction of the central axis. The disc spring 31 is compressible in the direction of the central axis, and exhibits an elastic force based on the amount of compression. In addition, since the disc spring 31 is continuous in the circumferential direction, the compression force is dispersed in the circumferential direction when compressed, and the amount of compressive deformation is large in a wide range in the vicinity of the portion where the compression force is applied. In the part away from the part where the force acts, the amount of compressive deformation is small.

  As shown in FIGS. 12 and 13, the disc spring 31 is slidably inserted in the clutch gear 73 so that the large diameter side comes into contact with the spring housing member 77. A surface on the friction plate side of the spring accommodating member 77 is recessed into the center gear 72 side to form a recess 77a. The outer diameter of the large diameter side of the disc spring 31 is larger than the inner diameter of the recess 77a, and the larger diameter side of the disc spring 31 can be accommodated in the recess 77a. The small diameter inner diameter of the disc spring 31 is slightly larger than the outer diameter of the clutch gear 73, and the disc spring 31 is slidable in the direction of the slide axis L1 with respect to the clutch gear 73, but with respect to the clutch gear 73. It is difficult to tilt. The thickness of the disc spring 31 is greater than the depth of insertion of the recess 77a in the direction of the slide axis L1. Therefore, as shown on the right side of FIG. 12, in the state where the disc spring 31 is housed most in the recess 77a and the disc spring 31 is not compressed, the small diameter side of the disc spring 31 extends from the recess 77a toward the friction plate. It protrudes.

  As shown in FIGS. 12 and 13, the thrust collar 32 is an annular member and is slidable to the clutch gear 73 so as to be positioned between the disc spring 31 and the friction plate closest to the spring accommodating member 77. Splined. An annular spacer S is provided between the disc spring 31 and the thrust collar 32, and the small diameter side of the disc spring 31 can contact the spacer S. The spacer S is spline fitted to the clutch gear 73 so as to be slidable. In general, since the design of the disc spring 31 is very difficult, the compression timing of the disc spring 31 can be easily changed by changing the thickness of the spacer S. Therefore, the thickness of the thrust collar 32 may be changed instead of the spacer S.

  With the above configuration, the disc spring 31 is interposed between the spring housing member 77 and the thrust collar 32 that do not rotate relative to the clutch gear 73. Therefore, the members do not rotate relative to each other, and there is almost no deterioration due to wear of the disc spring 31.

(About brake operation)
First, each state of the side brake 74 will be described with reference to FIG. When the clutch gear 73 gradually moves to the side brake 74 side based on the operation of the steering lever 8 from the state of the right side brake 74 shown in FIG. The clutch gear 73 and the center gear 72 are disengaged. Thereby, the driving force from the engine E is interrupted and the combine turns slowly. When the clutch gear 73 further moves toward the side brake 74, the flange portion 73 d comes into contact with the spring accommodating member 77, and the thrust collar 32 is pressed by the small diameter side of the disc spring 31 accommodated in the spring accommodating member 77. Then, the thrust collar 32 moves following the movement of the clutch gear 73 and comes into contact with the friction plate closest to the clutch gear 73. Thereafter, the gap between the first friction plate 74a and the second friction plate 74b is closed by the movement of the clutch gear 73. Finally, the gap between the first friction plate 74a and the second friction plate 74b disappears as in the state of the left side brake 74 shown in FIG. Until this state, a narrow pressure does not act on the first friction plate 74a and the second friction plate 74b, and the first friction plate 74a and the second friction plate 74b are relatively rotatable. A state in which the side brake 74 is not braked is a brake disengaged state as a “clutch disengaged state”. Further, the disc spring 31 is not compressed and deformed during the brake-off state.

  When the clutch gear 73 is continuously pressed, the disc spring 31 is compressed and deformed by the pressing force of the clutch gear 73. As a result, an elastic force based on the compression deformation of the disc spring 31 acts on the thrust collar 32, and the first friction plate 74a and the second friction plate 74b are narrowed by the thrust collar 32 and the stationary pressing portion 74d. As the narrow pressure increases, the relative rotation of the first friction plate 74a and the second friction plate 74b decreases due to the mutual friction, and finally the relative rotation stops. That is, the traveling device 2 is completely braked. This state is the brake applied state as the “clutch engaged state”. When the brake is applied, the combine turns in a right or left direction. A state between the brake disengaged state and the brake applied state, and a state in which both friction plates are rotating relative to each other while being subjected to the action of a narrow pressure, is a half brake state as a “half clutch state”.

(About compression deformation of disc spring)
The disc spring 31 performs its function in the half brake state. In the half brake state (the state of the left side brake 74 shown in FIG. 12), there is no gap between the first friction plate 74a and the second friction plate 74b. Therefore, the disc spring 31 is sandwiched between the spring housing member 77 and the thrust collar 32 and is compressed and deformed by the pressing force of the clutch gear 73. When the disc spring 31 is compressed, it compresses and deforms by dispersing the compressive force (the pressing force of the clutch gear 73) in the circumferential direction. The amount of compressive deformation of the disc spring 31 near the contact portion between the large diameter side where the compressive force acts and the recess 77a is large, and the amount of compressive deformation of the disc spring 31 in the portion away from the portion where the compressive force acts is small. Therefore, even if a portion of the flange portion 73d protrudes toward the friction plate due to the inclination of the flange portion 73d (clutch gear 73) and the unevenness of the surface pressed by the flange portion 73d, the disc spring 31 is in contact with the protruding portion. Is greatly compressed, and the pressing force is transmitted to the thrust collar 32 in a state where the influence of the inclination of the clutch gear 73 is mitigated. That is, the disc spring 31 and the thrust collar 32 come into uniform contact over the entire circumference, and come into surface contact at least at a certain portion. As a result, the thrust collar 32 comes into contact with the friction plate in an appropriate posture, and no abnormal noise is generated due to a single contact.

  Thus, the small-diameter side of the disc spring 31 is tiltable with respect to the slide axis L1, and the small-diameter side of the disc spring 31 corresponds to the “tilting member” according to the present invention.

  Thereafter, when the pressing force of the clutch gear 73 continues to increase, the disc spring 31 continues to undergo compression deformation as the pressing force increases. Finally, as shown in FIG. 13, when the brake is applied, the disc spring 31 is completely accommodated in the recess 77 a including the small diameter portion, and the spring accommodating member 77 comes into contact with the thrust collar 32. However, since the rotation of the first friction plate 74a is absolutely stopped when the brake is applied, no abnormal noise is generated even when the spring accommodating member 77 contacts the thrust collar 32. In this way, the disc spring 31 functions throughout the half brake state, and no abnormal noise is generated.

[Fifth embodiment]
In the above-described embodiment, the disc spring 31 is provided between the spring accommodating member 77 and the friction plate closest to the spring accommodating member 77, but is not limited thereto. For example, as shown in FIG. 15, the disc spring 31 is provided between the stationary pressing portion 74d and the friction plate closest to the stationary pressing portion 74d. Similarly, the thrust collar 32 is disposed on the side of the disc spring 31 and the most stationary pressing portion 74d. It may be provided between the friction plates. The narrow pressure acting on the friction plate is due to the pressing force by the clutch gear 73 and the pressing force by the stationary pressing portion 74d which is the reaction of the pressing force. can get. In the present embodiment, the thrust collar 32 is spline-fitted to the projecting portion 74c so as to be slidable.

  Also in the above-described embodiment, in this embodiment, the direction of the disc spring 31 is determined only by the shape of the other part, and the small diameter side and the large diameter side are arranged in any direction. It doesn't matter. Further, the thrust collar 32 may not be provided, and the disc spring 31 may be in direct contact with the friction plate. The disc spring 31 does not have to be formed of a single piece, and a plurality of pieces may be used to adjust the elastic force.

[Sixth Embodiment]
In the above-described embodiment, an example in which the disc spring 31 is used as the automatic inclination correction unit has been described. However, instead of the disc spring 31, a plurality of coil springs 33 are arranged uniformly on the circumference around the support shaft 71. It is also possible to use an automatic inclination correction unit. In this case, the larger the number of coil springs 33, the better. Even if the coil spring 33 is provided between the flange portion 73d and the friction plate closest to the flange portion 73d, as shown in FIG. 16, the coil spring 33 is provided between the static press portion 74d and the friction plate closest to the static press portion 74d. May be.

[Other alternative embodiments]
(1) In the above-described embodiment, the combine provided with the steering lever 8 as the steering operation tool has been described. However, the steering operation tool may be a steering handle.

(2) In the above-described embodiment, the side brake 74 brakes the traveling device 2, but is not limited to this. Although not shown in the figure, a gear transmission that takes out the engine driving force separately and converts it into a driving force that is higher or lower than the driving force transmitted to the traveling device 2 via the center gear 72, and the side brake 74 is braked. The driving force from the gear transmission may be transmitted to the traveling device 2 on the turning direction side when the state is reached. The driving force generated by the gear transmission may be a driving force in the backward direction.

  The swivel transmission device according to the present invention is not limited to a combine, but can be applied to agricultural work machines such as rice transplanters and lawn mowers and construction work machines such as backhoes as long as it has a wet multi-plate clutch. .

2 Traveling devices 8 Steering lever (steering control tool)
31 Belleville spring (automatic tilt correction part)
33 Coil spring (automatic tilt correction part)
40 Automatic inclination correction part 41 Base member 41a Contact surface (surface facing a base member)
42 Ball member 43 Outer member (tilting member)
44 Inner member (tilting member)
62 Rotating transmission device 64 Drive transmission gear 71 Support shaft 72 Center gear (drive gear)
73 Clutch gear (slide member)
73d Flange part (moving pressing part)
74 Side brake (wet multi-plate clutch)
74a First friction plate 74b Second friction plate 74c Projecting portion (member on the mission case side)
74d Stationary pressing portion 77 Spring accommodating member (moving pressing portion)
E Engine MC Mission case L1 Slide axis O Point

Claims (4)

Based on the operation of the steering operation tool, a turning transmission device for a work vehicle provided with a pair of left and right traveling devices that can be driven separately,
A driving gear supported by a support shaft installed in the transmission case and driven to rotate by the driving force of the engine;
The left and right sides of the drive gear are externally rotatably mounted on the support shaft, and are always engaged with a pair of left and right drive transmission gears respectively linked to the pair of left and right traveling devices, and the steering operation is always performed. A pair of left and right slide members that can move relative to each other along the support shaft by operation of a tool and can be engaged with the drive gear separately;
A first friction plate that is slidably engaged with the slide member and a second friction plate that is slidably engaged with a member on the transmission case side on both the left and right sides of the drive gear. A plurality of sheets are alternately arranged, and the slide member is separated from the drive gear after the slide member and the drive gear are disengaged, thereby being provided on the slide member and the first friction. The first friction plate includes a moving pressing portion that can press the plate or the second friction plate along the support shaft, and a stationary pressing portion that is a member on the mission case side and faces the moving pressing portion. And a pair of left and right wet multi-plate clutches configured to clamp the second friction plate,
It is opposed to the friction plate closest to the moving pressing portion or the friction plate closest to the stationary pressing portion, and is tiltable with respect to the slide axis of the slide member by the pressing of the moving pressing portion. And an annular tilting member disposed around the support shaft, and between the moving pressing portion and the friction plate closest to the moving pressing portion, or between the stationary pressing portion and the most stationary pressing portion. An automatic inclination correction unit interposed between the friction plate on the side of
The automatic inclination correcting unit is
An annular base member externally fitted to the slide member;
The tilting member that is extrapolated to the slide member and presses the friction plate on the most moving pressing portion side through the base member by pressing of the moving pressing portion;
A plurality of ball members interposed between the base member and the tilting member,
At least one of the surface of the base member that faces the tilting member and the surface of the tilting member that faces the base member has a spherical surface shape centered on a point on the slide axis. A turning transmission device for a work vehicle that is formed to follow . Based on the operation of the steering operation tool, a turning transmission device for a work vehicle provided with a pair of left and right traveling devices that can be driven separately,
A driving gear supported by a support shaft installed in the transmission case and driven to rotate by the driving force of the engine;
The left and right sides of the drive gear are externally rotatably mounted on the support shaft, and are always engaged with a pair of left and right drive transmission gears respectively linked to the pair of left and right traveling devices, and the steering operation is always performed. A pair of left and right slide members that can move relative to each other along the support shaft by operation of a tool and can be engaged with the drive gear separately;
A first friction plate that is slidably engaged with the slide member and a second friction plate that is slidably engaged with a member on the transmission case side on both the left and right sides of the drive gear. A plurality of sheets are alternately arranged, and the slide member is separated from the drive gear after the slide member and the drive gear are disengaged, thereby being provided on the slide member and the first friction. The first friction plate includes a moving pressing portion that can press the plate or the second friction plate along the support shaft, and a stationary pressing portion that is a member on the mission case side and faces the moving pressing portion. And a pair of left and right wet multi-plate clutches configured to clamp the second friction plate,
It is opposed to the friction plate closest to the moving pressing portion or the friction plate closest to the stationary pressing portion, and is tiltable with respect to the slide axis of the slide member by the pressing of the moving pressing portion. And an annular tilting member disposed around the support shaft, and between the moving pressing portion and the friction plate closest to the moving pressing portion, or between the stationary pressing portion and the most stationary pressing portion. An automatic inclination correction unit interposed between the friction plate on the side of
The automatic inclination correcting unit is
An annular base member externally fitted to the slide member;
The tilting member that is extrapolated to the slide member and presses the friction plate on the most moving pressing portion side through the base member by pressing of the moving pressing portion;
A plurality of ball members interposed between the base member and the tilting member,
The turning transmission device for a work vehicle, wherein the tilting member is tiltable with respect to the base member by rotation of the ball member. When viewed from the direction perpendicular to the slide shaft core, at least one of the surface of the base member facing the tilting member and the surface of the tilting member facing the base member is opposed to the other. 3. The turning transmission device for a work vehicle according to claim 2, wherein the turning transmission device is formed in an inclined shape that approaches the slide axis as it approaches the surface. The at least one of the surface facing the tilting member and the surface facing the base member is formed so as to follow a spherical surface shape centered on a point on the slide axis. 4. A turning transmission device for a work vehicle according to 3.

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